The present invention relates generally to breathing devices, and will be specifically disclosed as a respiratory circuit capable of in vivo sterilization.
In many medical situations, the pulmonary functions (i.e., relating to the lungs) of a patient need to be monitored, controlled or accessed, and in many circumstances for days at a time. To achieve this, the medical field often uses a respiratory circuit which is connected to a ventilator, which is sometimes referred to as a respirator. Typically, respiratory circuits include a breathing tube (e.g. endotracheal tubes, tracheostomy tubes, laryngeal mask airways, and the like) that acts as the interface between the patient and the respiratory circuit. For instance, an endotracheal tube is inserted through the mouth or nasal passages of the patient and into the trachea. Usually, a balloon or cuff surrounding the inserted end of the tube is inflated to provide a seal between the endotracheal tube and the trachea. Once sealed, the patient breathes through the endotracheal tube.
Once a breathing tube is connected to a patient, other components of the respiratory circuit are coupled to the breathing tube. Usually, a ventilator tube links the breathing tube with a ventilator which monitors, and if necessary can control, the pulmonary functions of the patient. Other components, such as junctions, moisture traps, filters, humidifiers and the like, optionally can be added to the respiratory circuit. For instance, drug delivery systems can be added to the respiratory circuit to delivery aerosolized medicine to the lungs of the patient. In some circumstances, medical care givers require access to the lungs and/or trachea of the patient. For example, suction catheters are used to remove secretions in a patient""s lungs. In such circumstances, special junctions can be added to the respiratory circuit which allow such access without interrupting the monitoring or control of the pulmonary functions.
An ongoing challenge with respiratory circuits is maintaining a sterile environment. Indeed, one clinical study has concluded that xe2x80x9ctrying to maintain a sterile ventilator circuit for 24 hours is a difficult and perhaps impossible task.xe2x80x9d Contaminated Condensate in Mechanical Ventilator Circuits, Donald E. Craven, et al., Concise Clinical Study, p. 627. Due to the inherent moisture and warmth, respiratory circuits provide superb conditions for microbiological growth or colonization. Once colonization has started, the microbiological growth can easily spread to the patient, either airborne or through moisture condensation running down into the patient""s lungs, thus risking infections and complications, often resulting in pneumonia.
The problem of respiratory circuit colonization is especially prevalent within breathing tubes. For instance, studies has documented the health risks from colonization in endotracheal tubes, sometimes called a biofilm, which can be so extensive that the walls of the endotracheal tube become slimy and sticky. See Nosocomial pulmonary infection: Possible etiologic significance of bacterial adhesion to endotracheal tubes, Frank D. Sottile et al., Critical Care Medicine, Vol. 14, No. 4, p. 265. Due to the close proximity to the patient""s lungs, any microbiological growth in a breathing tube can easily spread to the patient""s lungs. Condensed moisture can run down the breathing tube, over the biofilm and into the patient""s lungs. Additionally, chunks of the biofilm can actually fall off the breathing tube and into the patient""s lungs.
Accordingly, an object of the invention is to provide an improved respirator circuit.
Another object of the invention is to provide a respirator circuit capable of sterilization while connected to a patient.
Still another object of the present invention is to provide an endotracheal tube capable of in vivo sterilization.
Yet another object of the present invention is to provide a respirator circuit junction capable of vivo sterilization.
Additional objectives, advantages and novel features of the invention will be set forth in the description that follows and, in part, will become apparent to those skilled in the art upon examining or practicing the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
One aspect of the present invention is an apparatus for in vivo sterilization of a respiratory circuit. A breathing tube has a proximal end, a distal end and a lumen extending between the proximal and distal ends. The lumen defines at least a portion of a respiratory circuit. A ventilator tube is in fluid communication with the proximal end of the breathing tube. The ventilator tube defines at least a portion of the respiratory circuit and has an inhalation portion and exhalation portion. One or more light sources irradiate at least a portion of the respiratory circuit. The light sources emit ultraviolet radiation for sterilizing the respiratory circuit.
Another aspect of the present invention is an endotracheal tube. A tube is adapted for insertion into the trachea of a patient. The tube has a proximal end, a distal end, and a tube wall having an inner surface and an outer surface. A light source emits ultraviolet radiation. The light source is positioned relative to the tube to bathe at least a portion of the inner surface of the tube wall with ultraviolet radiation.
Still another aspect of the present invention is a respiratory circuit junction. A tube port is adapted to interface with a breathing tube. A line port is adapted to interface with a ventilator line. A flow path extends between the tube and line ports. A catheter having a proximal end and a distal end is received by a catheter port connected to the flow path. The catheter port is dimensioned such that the catheter can be axially moved relative to the catheter port. The catheter port is aligned relative to the tube port such that the distal end of the catheter can be inserted into a breathing tube connected to the tube port. A light source capable of emitting ultraviolet radiation is positioned to irradiate at least a portion of the catheter.
Still other aspects of the present invention will become apparent to those skilled in the art from the following description of a preferred embodiment, which is by way of illustration, one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions are illustrative in nature and not restrictive.